Correct Answer: 52.5

Solution : From the given graph,
The total number of students participating in the exhibition = 45 + 30 + 60 + 75 = 210
The number of classes = 4
The average number of students participating in the exhibition = $\frac{\text{The total number of students participating in the exhibition}}{{\text{The number of classes}}}$
The average number of students participating in the exhibition = $\frac{210}{4}$ = 52.5
Hence, the correct answer is 52.5.

Correct Answer: Chemical change

Solution : The correct option is Chemical change.

When milk is converted into curd, it is a chemical change. This transformation involves the fermentation of milk by beneficial bacteria, such as Lactobacillus, which consume the lactose (milk sugar) and produce lactic acid. The production of lactic acid changes the composition and properties of the milk, giving it a thicker texture and a sour taste, which are characteristic of curd or yoghurt. This chemical change is irreversible, as you cannot easily revert curd into milk with the same properties it had before the transformation.

Correct Answer: 3 – 39

Solution : Let's check the options –
First option: 7 – 49; (7)² = 49
Second option: 2 – 4; (2)² = 4
Third option: 5 – 25; (5)² = 25
Fourth option: 3 – 39; (3)² = 9 ≠ 39

The fourth option does not fit the pattern. Hence, the fourth option is correct.

Correct Answer: Rs. 4000

Solution : Let $2X = 3Y = 4Z = k$
$X =\frac{k}{2}, Y = \frac{k}{3}, Z = \frac{k}{4}$
The sum of shares of all of them together = 13000
⇒ $\frac{k}{2} + \frac{k}{3} + \frac{k}{4} = 13000$
⇒ $\frac{6k+4k+3k}{12}=13000$
⇒ $\frac{13k}{12}=13000$
⇒ $k = 12000$
$\therefore$ Share of $Y = \frac{1}{3}\times 12000=4000$
Hence, the correct answer is Rs. 4000.

Correct Answer: Shy

Solution : The correct choice is the first option.

Introverts are typically reserved people.

Outspoken, social, and bold are terms used for people who are not as reserved as introverts.

The sentence describes the girl as being painfully introverted, which suggests that she is extremely shy and uncomfortable around other people. The other options are not as appropriate because they do not convey the same sense of social awkwardness.

Therefore, shy will be the correct choice.

Correct Answer: 2430

Solution : The first 2 digit number is 10 and the last two-digit number is 98.
Sum = $\frac{n}{2}(\text{first term + last term})$
Number of terms = $\frac{(98 - 10)}{2} + 1$ = 45
Now, we can find the sum:
Sum = $\frac{45}{2}(10 + 98)$
⇒ Sum = $45\times54$
⇒ Sum = 2430
Therefore, the sum of all two-digit even numbers is 2430.
Hence, the correct answer is 2430.

Correct Answer: 2400

Solution : The correct answer is 2400.

China's monarchs started constructing the Great Wall some 2400 years ago, before the Mauryan empire. Its purpose was to keep pastoral people away from the empire's northern frontier.

Correct Answer: Barter exchanges require a double coincidence of wants.

Solution : The correct option is Barter exchanges require a double coincidence of wants.

The most problematic and primary difficulty of barter exchanges compared to money-based exchanges is the requirement of a double coincidence of wants. In barter, both parties must have something the other wants, creating complexity and inefficiency.

Correct Answer: 1,10,000

Solution : $P=P{_0}​×(1+r)^t$
where: $P$ is the present population, $P{_0}$​ is the past population, $r$ is the annual growth rate (as a decimal), and $t$ is the number of years.
Given, $P{_0} = 133,100$
$r = 10\%$
We have to find the population 2 years ago ($t=−2$ years)
$133100=P{_0}×(1+\frac{10}{100})^{2}$
$⇒P{_0}=133100×(\frac{11}{10})^{−2}$
$⇒P{_0}=133100×\frac{1}{(\frac{11}{10})^2}$​
$⇒P{_0}=133100×\frac{100}{121}$
$⇒P{_0}=1,10,000$
Hence, the correct answer is 1,10,000.

Correct Answer: 90 days

Solution : Given: A can do in one day three times the work done by B in one day. They together finish $\frac{2}{5}$th of the work in 9 days.
Let the efficiency of B = $a$ units,
So, the efficiency of A = 3$a$ units
Here, $\frac{2}{5}$th of the work is done by them in 9 days.
So, the total work is done by them in (9 × $\frac{5}{2}$) = $\frac{45}{2}$ days
We know,
Total work = Total efficiency × Number of days = $(a+3a)×\frac{45}{2}$ = 90$a$ units
$\therefore$ The required days for B to do the work alone = $\frac{90a}{a}$ = 90 days
Hence, the correct answer is 90 days.